Authorities announced a joint investigation by state and local police and prosecutors in both Montgomery and Susquehanna counties. Their investigation led to the arrest of the victim's son David St. Onge, Sr. as well as the victim's grandson, David St. Onge Jr.

Onge, Sr. allegedly admitted to striking his father in the head and then conspiring with his son Onge, Jr. to dispose of the body. Onge, Sr. also allegedly stole items from his father and sold them for profit.